Inflation valve for preventing unauthorized deflation of tires



Aug. 26, 1958 L. DICKENS 2,849,017

INFLATION VALVE FOR PREVENTING UNAUTHORIZED DEFLATION 0E TIRES Filed Dec. 17, 1954 r F/ZI-E 3 Z/ Illlllli II! II Ill 1 6 J IIIIIIIIII' /7 iiillll-llllllll IN V EN TOR.

y/mw/ United States Patent INFLATION VALVE FOR PREVENTING UNAUTHORIZED DEFLASTION OF TIRES Leslie-Dickens, Eureka;- M'oz; assignor to The Firestone Tgre Rubber- Company; Akron, Ohio, a corporation 0 '41-.

Application December 17, 1954, Serial Nil-47391.1 1' Claim (Cl. 1 37Z2'3)- This invention relates. to; tire innerttub'e type. valves used: 101 conduct inflationary: air to and. from a tubeless pneumatic vehicular tire. Such valves; when used with tubeless tires; are commonly: attached. in: fluidi-tight relation with. the tirerrimx at the rim: valvei hole:

Tire manufacturers that: sell" tires on:- the basis of the mileage the tires: run' and: the .companie's that operate large taxi, bus or truck fleets. who buy' tires on such 'mileage basis,. are confronted with the problem of maintaining the proper air pressure: inthetires. As is: well known, the; mileage received f'romtires run under-infiated is substantially less: than from tires run properlyinflated The experience: of saidfleet operators has established that many drivers will disregard: instructions and partially de flate the tires on vehicles they are driving. This deflation is done by simply pressing. onthevalve deflator. pin until enough air has escaped to suit the driverspurpose, which is to produce a softer ride than proper tire inflation gives.

Formany years. tire. manufacturers and said fl'eetioperators have; unsuccessfully soughtan answer to this'\pr'oblemrof. loss: of tire mileagefromunauthorized deflating. of tires.

It is an object of the present invention to solve the problem of unauthorized deflation of tires by simple inexpensive meansgattached.tothebase;end of the. inflating valve stem; said means. permitting unobstructed: inflation and preventing deflation through the valve, said means being inaccessible for deflation except by demounting the tire.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing.

In the drawing:

Fig. 1 is a sectional view of a tire rim showing an inflating valve stem embodying the present invention associated with said rim in operative relation therewith;

Fig. 2 is a plan view of a blank of thin metal before it is stamped to a predetermined shape preparatory to being attached to the base of said stem;

Fig. 3 is aside view of the blank shown in Fig. 2 as it appears after being formed to a shape adapted for attachment to the base portion of said valve;

Fig. 4 is an exploded view of the valve stem shown in Fig. l and its associated parts including a fragment of the rim;

Fig. 5 is an enlarged fragmentary sectional view of Fig. 1 illustrating the relative positions the elements shown in Fig. 4 occupy in their final assembly and during inflating of a tire mounted on said rim; and

Fig. 6 is the same as Fig. 5 except the relative position of a gasket of a check valve is shown as it would appear if an elongated object were passed into the other end of the valve stem and pressed against said diaphragm in an effort to deflate a tire.

Referring to Figs. 1 and 4, it will be seen that a valve designated generally as 10 is attached to tire rim 5 at a rim valve hole 6. Valve 10 comprises a barrel 11, base 12, externally threaded end portion 13 opposite base 12,

Patented Aug. 26, 1958 an enlarged externally threaded barrel portion 14 and an embossed annular table formed on the axially outer end of said base. A dust cap 15 is threaded'up'on'end 13 of stem- 10. It is to be understood that said externally threade'd end- 13- is also internally threaded and receives in threaded relation tire inner tube valve'insides which function'i'n: the usual manner'oftire inner tube valve in= sides relative to barrel 11 to permit tire inflationary aii" to* pass through said barrel and rim intoa tire mounted on'said Stein 1'0 has associated therewiththe usual elements presently being used' commercially to attach valve stems to tubeless tire rims; These" attachment elements include a rubber Washer 16 which washer has a base portion 17 that is substantially equal to the base 12' of the valve stem-and a reduced portion 18. Washer lfi'has a" central holether'ethrough of a sizes'othe washer fits about barrel portion 14. I

Portion-1 8* extends axially outwardly of the rim into rim valvehol'e 6. A rubber washer19fits'arouud Barrel portion 14 and contacts the outer surface of rim 5 at sai trriin valiiehole. A metal washer 20 is disposed on stem 10 in contact with washer 19 and a nut 21 is in threaded relation with portion 14in contact with washer 20 all as -shown by Fig. 1.

An important feature of the present invention is an auxiliary valve referred to generallyas 30,- attached to the base" 12 ofval've' 1h. Valve3il comprises a thin disk 31 preferably composed' of'rubber or ruhber likemate'ria'l housed in' a chamber 35 between the-base12 of valve 10' and ahousing" 3'2"attached'- to base 12; Housing, 32 is preferably c'omposed of thin brass stamped inthe form of ahollow round pan of a width somewhat less than the widtli ordiameter of base 12 Housing 32 has" lugs 33' turned over the edge of base 12- and extending under washerld as shown by'Figs; Sand Got the drawing; the lugs 33- are so-t'urn'ed over the edge'of base 12 that the edge ofthe housing referred to as 34* is spaced a short distance from base 12 so that air durin'g'tireinfiatingQ can pass-freely into and from said housing; As' will best be seen by reference to Fig. 5 the disk 31 is of a thickness relative to the depth of chamber 35 that when said disk is in flat contact with the bottom of the pan of housing 32, as is the case during inflating of a tire, that air may pass freely from valve 10 through valve 32. In the event valve 10 is manipulated to start deflation of a tire mounted on rim 5 through a passageway 37 through barrel 11, then the movement of air through chamber 35, of valve 32, causes the valve or disk 31 to contact the base 12, and thereby close. the entrance 36 of the passage 37 making deflation impossible.

The assembly shown in Fig. l is made by stamping out the housing blank 32 from a thin sheet of brass or other material found satisfactory. This blank is then formstamped to the pan form illustrated in Fig. 3 after which the thin gasket 31 is placed in the pan of housing 32 and the lugs 33 turned over the edge of valve base 12 so as to attach housing 32 thereto with the edge 34 of said pan spaced from base 12 as shown in Fig. 5. Next gasket 16 is passed onto barrel 11 and pressed down against base 12 and then the capped end of barrel 11 is passed through rim valve hole 6 until reduced portion 18 of gasket 16 enters rim valve hole 6 and base portion 17 contacts the inner surface of said rim adjacent the rim valve hole. The next steps are to pass gasket 19 onto barrel 11 until it contacts said tire rim and then rigid washer 20 against gasket 19, after which nut 21 is run down on the threads of barrel portion 14 until the gaskets 16 and 19 are clamped firmly against rim 5 adjacent said valve stem hole thereby providing an air-tight attachment of valve 10 to rim 5.

When the assembly shown in Fig. 1 is used by the operators of large taxi, bus or truck fleets, a tubeless tire mounted on rim 5 is carefully inflated using a type of tire inflator now in common use that inflates a tire to a selected pressure to the pressure desired by the fleet operator. If a driver of the vehicle on which the tire is mounted attempts to partially deflate the tire by the usual manner of removing cap and pressing the deflator pin in the valve in the threaded end of barrel 11 the movement of air from a tire being deflated through chamber 35 of housing 32 causes disk 31 to flutter against valve base 12 and prevent exit of air from the tire by disk 31 closing said entrance 36. If said driver of the vehicle endeavors to open valve to permit deflation of the tire by removing the said valve insides to gain access to valve 30, as for example, by passing a wire or elongated object such as 40 into valve 30 as shown in Fig. 6, the housing 32 prevents displacement of disk 31 from its sealing contact with base 12. Disk 31 being of rubber or rubbery-like material will be pressed, by an object such as a wire 40, from contact with base 12 immediately about the entrance 36 to passage 37 but the internal air pressure in chamber will hold the edge portion of disk 31 firmly against base 12 in air-tight contact therewith whereby such unauthorized attempts to deflate the tire is defeated.

The only way to deflate the tire without mutilating valve 30 is to loosen nut 21 and press barrel 11 through valve hole 6 until gaskets 16 and 19 are loosened enough to permit the escape of air through the rim valve hole. Deflating by this method is done by the fleet operator in a service terminal or garage when a tire is to be replaced or repaired. While such deflation is a simple matter as garage operation and where complete deflation is to be done to demount the tire it is sufficiently involved to completely discourage a roadside attempt to so deflate. It is further pointed out that when deflation is done by loosening nut 21 as just described, the amount of deflation cannot be accurately controlled and washers 16 and 19 may require replacement in order to provide an airtight seal. It has been found that drivers will not tamper with valves embodying the present invention and tire cost of operating fleets of vehicles mentioned hereinabove is substantially reduced.

The detailed description of the particular embodiment of the invention illustrated and described herein is not to be construed as limiting the invention thereto. It is to be understood that the invention is useful with any type of valve used with tubeless tires whenever the valve 30 may be incorporated therewith. The invention includes all features of patentable novelty residing in the foregoing description and the accompanying drawings.

I claim:

A tamper-proof valve for admitting inflationary air into a pneumatic tire and retaining it therein, said valve comprising a valve stem having a central passage extending longitudinally therethrough, an annular seat disposed about one end of said passage and having an outer diameter at least four times greater than the diameter of said passage, an imperforate disc positioned adjacent said seat and closing said inner end of said passage when in contact with said seat, a support having a portion holding said disc against lateral displacement away from said seat and having a second portion spaced from said seat a distance approximately twice the thickness of the disc, thereby permitting said disc to move axially away from said seat under the force of inrushing air under pressure in said central passage and to move against said seat to close off said passage in response to the pressure of the air acting in the opposite direction, said disc being of flexible material and having a diameter corresponding to the diameter of said seat to permit the central portion of said disc to be displaced axially from the inner end of said passage into contact with said second support portion while the outer annular portion of said flexible disc retains sealing contact with said seat.

References Cited in the file of this patent UNITED STATES PATENTS 1,469,966 Schweinert Oct. 9, 1923 1,797,280 Zerk Mar. 24, 1931 2,587,470 Herzegh Feb. 26, 1952 2,685,907 Waddell Aug. 10, 1954 FOREIGN PATENTS 968,435 France Apr. 19, 1950 975,788 France Oct. 17, 1950 

